Aqueduct Gela-Aragona (Italy)

THE PROJECT CONSISTS IN THE RENEWAL OF THE ENTIRE WATER SUPPLY MAIN, REPLACING THE EXISTING FIBREGLASS PIPING WITH A DUCTILE IRON PIPE, AND A GENERAL MODIFICATION OF THE HYDRAULIC SCHEME OF THE MAIN CONVEYOR, WITH THE INTRODUCTION OF 3 TUNNEL TANKS ALONG THE LINE AND BOOSTER TYPE PUMPING STATIONS INSTEAD OF THE EXISTING ONES WITH MULTISTAGE VERTICAL AXIS PUMPS AND COLLECTING TANKS.

Project: Restructuring of the Gela–Aragona aqueduct

Location: Sicily Island, Italy

Client: Special Commissar for the Water Emergency (Sicily) for Regional Government of Sicily

Cost of total Works: €69,514,000

Services: Final and Detailed Designs, Supervision of construction

Period: 2002 - 2011

In recent years the island of Sicily has suffered large periods of drought, mainly due to the scarcity of rainfall and mismanagement of the resources, compounded by waste during distribution due to the poor condition of the aqueduct.

The project aims to upgrade the existing pipelines, avoiding waste of water and optimizing water resources in the area. In fact, once the aqueduct has a steady state operation, the desalinated water from the desalination plant of Gela will probably no longer be necessary for the proper functioning of the system.

The new water supply system, which will also be connected to the water supply system of Favara di Burgio, the Voltano aqueduct and the conduit from the Blufi dam, is capable of satisfying the potable water demands of the entire south-central area of Sicily. The tanks in tunnels, which have a total capacity of over 20,000 m³, can provide not only a daily but a seasonal regulation of the water supply. Moreover, the tunnels allow the temperature regulation of the water supply which tends to be rather high during some summer days. The aqueduct system adopted in this project is complex, as it comprises about 100 km of pipes spaced by pumping stations, support head stations and tanks.

The logic is also complicated, because there is no single flow direction, since the water could come from either the Agrigento side (Belvedere tank) or the Gela side (Orange tank).

In order to have a two-way system, several measures have been applied, such as the placing of multiple sensors along the aqueduct and the insertion of series of remotely controlled motorized valves over the entire water network. Indeed, the new aqueduct Gela - Aragona is designed to operate automatically through a centralized management from the control centre of San Biagio Mendolito through a supervisory system that allows optimizing system operation.

The works of reconstruction of the Gela - Aragona aqueduct also concern the construction of new reservoirs and expanding and upgrading the existing ones.

The works in question include:

New cover tank of Safarello

New cover tank of Rocca Corvo

Modification of the existing St. Leo tank

Modification of the existing Safarello tank

Modification of the existing Licata tank

Modification of the Rupe Atenea tank

Modification of the Belvedere tank

The booster type pumping stations with revolution gage, used for controlling the parallel pump groups, permits the optimization of the pumps operation, minimizing energy waste and protecting the piping against water hammer phenomena due to sudden pump arrests. The design system offers great reliability in terms of durability of materials (ductile iron instead of fibreglass), protection against irregular movement phenomena (inverter and revs gage) and general redundancy of the system (interconnection of the conduits and parallel pumps). Furthermore, from the energy point of view the operation of the whole system has been optimized, allowing significant savings with respect to the present situation. Thanks to this aqueduct, the southern/central parts of Sicily region are guaranteed a supply of fresh water throughout the year, without risk water shortage.